THE FORMATION OF FAT IN THE ANIMAL BODY. 187 



cheese which could not be changed by the ripening process, viz, the 

 phosphoric acid and calcium, also found that in the ripening of "Back- 

 stein " cheese there was no formation of fat. 



W. von Schneider ' investigated the making of wax by bees, and from 

 his analyses of pollen he showed that Berlepsch's esi^eriment, in which 

 bees were fed with 117 gm. of pollen, indicated that Voit's position was 

 incorrect, and pointed rather to the foruiation of wax from carbohy- 

 drates. The 117 gm. of pollen contained 22 gm. of protein. This could 

 yield at most 12 gm. of wax", but 33 gm. of wax was made. Of this 12 

 gm. could have been formed from protein, 10 gm. could have existed as 

 wax previously formed in the bodies of the bees, and the remaining 11 

 gm. must have been formed from carbohydrates. E. Erlenmeyer and 

 A. von Planta-Reichenau^ made investigations with bees, feeding them 

 sugar (rock candy). From each 8 gm. of sugar consumed there was 

 produced 1.589 gm. of fat which could not possibly have been formed 

 from protein. The nitrogen and fat content of the bees themselves 

 remained unchanged during the experiment — that is, wax was not 

 formed at the expense of their own body protein or fat. 



In 1881 the publication of a long series of articles on the feeding of 

 farm animals was begun, which indicated even more decidedly the for- 

 mation of fat from carbohydrates, and taken in connection with the 

 experiments of Lawes and Gilbert, mentioned above, and the experi- 

 ments with bees just cited, placed this theory beyond all doubt. 



The next experiment which should be cited was made in 1876 and 

 1877 by Henneberg, Kern, and Wattenberg with sheep. This was the 

 first experiment with Herbivora in which the attemjDt was made to 

 prove the formation of fat from carbohydrates. Henneberg first called 

 attention to this experiment in its relation to the formation of fat in 

 1881. Its bearing on the question was observed before this by the 

 investigators, but was first pointed out by E. von Wolft". A sheep was 

 fed for 70 days with lucern hay, maize meal, and turnips. Only 6,872 

 gm. of fat could have been formed from the fat and protein in the food. 

 However, 9,730 gm. was actually found. 



It is possible to criticise these experiments. For instance, this animal 

 may have consumed more food and more protein than other animals in 

 the same series, or too large a factor may have been used in computing 

 the amount of fat formed from protein. But granting all this, the 

 experiment still shows that there was a direct formation of fat from 

 carbohydrates. 



F. Soxhlef showed that according to the investigations of Schulze 

 and Barbieri the potatoes which Weiske a.nd Wildt fed in tlieir experi- 

 ments contained from 35 to 52.6 per cent of non-albuminoid nitrogen, 

 and that therefore only 67 to 85 per cent of the fat formed could have 



' Ann. Chem. und Phann., 162 (1872), p. 235. 



^Bienen Ztg., 1878, No. 16, p. 181; and 1880, No. 1, p. 1. 



" ZtscLr. landw. Ver. Bayeiu, 1881, p. 423, 



6128— No. 3 2 



